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This paper presents the features and benefits of legacy IPv4 network migration towards major two latest networking paradigms viz. Internet protocol version 6 (IPv6) and the software-defined networking (SDN). These latest networking paradigms are the enabler of future generation networking so that the standards and requirements of fifth generation (5G) wireless networking can be achieved. Features and migration approaches of IPv6 and SDN will be separately discussed, then a joint migration approach of SDN and IPv6 network termed as SoDIP6 network migration will be presented, and the integration of SoDIP6 network as a backbone of 5G network will be introduced., Comment: This is an position/overview paper from the PhD thesis work of Dr. Babu R. Dawadi. 18 figures, 24 pages, 2 tables

This is the peer reviewed version of the following article: Dawadi, BR, Rawat, DB, Joshi, SR, Manzoni, P, Keitsch, MM. Migration cost optimization for service provider legacy network migration to software-defined IPv6 network. Int J Network Mgmt. 2021; 31:e2145, which has been published in final form at https://doi.org/10.1002/nem.2145. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving., [EN] This paper studies a problem for seamless migration of legacy networks of Internet service providers to a software-defined networking (SDN)-based architecture along with the transition to the full adoption of the Internet protocol version 6 (IPv6) connectivity. Migration of currently running legacy IPv4 networks into such new approaches requires either upgrades or replacement of existing networking devices and technologies that are actively operating. The joint migration to SDN and IPv6 network is considered to be vital in terms of migration cost optimization, skilled human resource management, and other critical factors. In this work, we first present the approaches of SDN and IPv6 migration in service providers' networks. Then, we present the common concerns of IPv6 and SDN migration with joint transition strategies so that the cost associated with joint migration is minimized to lower than that of the individual migration. For the incremental adoption of software-defined IPv6 (SoDIP6) network with optimum migration cost, a greedy algorithm is proposed based on optimal path and the customer priority. Simulation and empirical analysis show that a unified transition planning to SoDIP6 network results in lower migration cost.

This is the peer reviewed version of the following article: Dawadi, BR, Rawat, DB, Joshi, SR, Manzoni, P, Keitsch, MM. Migration cost optimization for service provider legacy network migration to software-defined IPv6 network. Int J Network Mgmt. 2021; 31:e2145, which has been published in final form at https://doi.org/10.1002/nem.2145. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving., [EN] This paper studies a problem for seamless migration of legacy networks of Internet service providers to a software-defined networking (SDN)-based architecture along with the transition to the full adoption of the Internet protocol version 6 (IPv6) connectivity. Migration of currently running legacy IPv4 networks into such new approaches requires either upgrades or replacement of existing networking devices and technologies that are actively operating. The joint migration to SDN and IPv6 network is considered to be vital in terms of migration cost optimization, skilled human resource management, and other critical factors. In this work, we first present the approaches of SDN and IPv6 migration in service providers' networks. Then, we present the common concerns of IPv6 and SDN migration with joint transition strategies so that the cost associated with joint migration is minimized to lower than that of the individual migration. For the incremental adoption of software-defined IPv6 (SoDIP6) network with optimum migration cost, a greedy algorithm is proposed based on optimal path and the customer priority. Simulation and empirical analysis show that a unified transition planning to SoDIP6 network results in lower migration cost.

OBJECTIVES To determine factors associated with parents who plan to vaccinate their children against influenza next year, especially those who did not vaccinate against influenza last year using a global survey. STUDY DESIGN A survey of caregivers accompanying their children aged 1-19 years old in 17 pediatric emergency departments in 6 countries at the peak of the coronavirus disease 2019 (COVID-19) pandemic. Anonymous online survey included caregiver and child demographic information, vaccination history and future intentions, and concern about the child and caregiver having COVID-19 at the time of emergency department visit. RESULTS Of 2422 surveys, 1314 (54.2%) caregivers stated they plan to vaccinate their child against influenza next year, an increase of 15.8% from the previous year. Of 1459 caregivers who did not vaccinate their children last year, 418 (28.6%) plan to do so next year. Factors predicting willingness to change and vaccinate included child's up-to-date vaccination status (aOR 2.03, 95% CI 1.29-3.32, P = .003); caregivers' influenza vaccine history (aOR 3.26, 95% CI 2.41-4.40, P < .010), and level of concern their child had COVID-19 (aOR 1.09, 95% CI 1.01-1.17, P = .022). CONCLUSIONS Changes in risk perception due to COVID-19, and previous vaccination, may serve to influence decision-making among caregivers regarding influenza vaccination in the coming season. To promote influenza vaccination among children, public health programs can leverage this information.

Objective: To determine if caregivers of children presenting to pediatric emergency departments (EDs) during the COVID-19 pandemic are delaying presenting to care for fear of contracting COVID-19. Methods: This was a pre-planned secondary analysis of a cross-sectional survey study of caregivers accompanying their children aged 0-19 years to 16 pediatric EDs in 5 countries from May to June 2020. An anonymous online survey, completed by caregivers via RedCAP, included caregiver and child demographics, presenting complaints, if they delayed presentation and whether symptoms worsened during this interval, as well as caregiver concern about the child or caregiver having COVID-19 at the time of ED visit. Results: Of 1543 caregivers completing the survey, 287 (18.6%) reported a delay in seeking ED care due to concerns of contracting COVID-19 in the hospital. Of those, 124 (43.2%) stated their child's symptoms worsened during the waiting interval. Caregiver relationship to child [mother] (OR 1.85, 95% CI 1.27-2.76), presence of chronic illness in child (OR 1.78. 95% CI 1.14-2.79), younger age of caregiver (OR 0.965, 95% CI 0.943-0.986), and caregiver concerns about lost work during the pandemic (OR 1.08, 95% CI 1.04-1.12) were independently associated with a COVID-19-related delayed presentation in multivariable regression analysis. Conclusions: Almost one in five caregivers reported delaying ED presentation for their ill or injured child specifically due to fear of contracting COVID-19 while in hospital, with mothers, younger caregivers, caregivers of children with chronic illness, and those concerned about lost work more likely to report delaying ED presentation. Keywords: COVID-19; Caregivers; Children; Emergency department; Presentation delay

This is the peer reviewed version of the following article: Dawadi, BR, Rawat, DB, Joshi, SR, Manzoni, P. Evolutionary gaming approach for decision making of Tier-3 Internet service provider networks migration to SoDIP6 networks. Int J Commun Syst. 2020; 33:e4399, which has been published in final form at https://doi.org/10.1002/dac.4399. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving., [EN] With the increasing number of Internet of Things (IoT) devices, current networking world is suffering in terms of management and operations with lack of IPv4 addresses leading to issues like network address translation (NAT) proliferation, security and quality of services. Software-defined networking (SDN) and Internet Protocol version 6 (IPv6) are the new networking paradigms evolved to address related issues of legacy IPv4 networking. To adapt with global competitive environment and avoid all existing issues in legacy networking system, network service providers have to migrate their networks into IPv6 and SDN-enabled networks. But immediate transformations of existing network are not viable due to several factors like higher cost of migration, lack of technical human resources, lack of standards and protocols during transitions, and many more. In this paper, we present the migration analysis for proper decision making of network transition in terms of customer demand, traffic engineering, and organizational strength with operation expenditure for network migration using evolutionary gaming approach. Joint migration to SDN-enabled IPv6 network from game theoretic perspective is modeled and is validated using numerical results obtained from simulations. Our empirical analysis shows the evolutionary process of network migration while different internal and external factors in the organization affect the overall migration. Evolutionary game in migration planning is supportive in decision making for service providers to develop suitable strategy for their network migration. The proposed approach for migration decision making is mostly applicable to fairly sustained service providers who lack economics, regulation/policy, and resources strengths.

[EN] The logical separation of the data plane and the control plane of the network device conceptually defined by software-defined networking (SDN) creates many opportunities to create smart networking with better efficiency for network management and operation. SDN implementation over telecommunications (Telcos) and Internet service provider (ISP) networks is a challenging issue due to the lack of a high maturity level of SDN-based standards and several other critical factors that are considered during the real-time migration of existing legacy IPv4 networks. Different migration approaches have been studied; however, none of them seem to be close to realizing implementation. This paper implements the SDN-IP and Open Network Operating System (ONOS) SDN controller to migrate legacy IPv4 networks to multi-domain software-defined IPv6 (SoDIP6) networks and experimentally evaluate the viability of joint network migration in the ISP networks. We present results using extensive simulations for the suitable placement of the master ONOS controller during network migration by considering minimum control path latency using optimal path routing and the breadth first router replacement (BFR) technique. Our empirical analysis and evaluations show that the identification of the median router to attach the master controller and router migration planning using BFR give better results for carrier-grade legacy networks' migration to SoDIP6 networks.

This is the peer reviewed version of the following article: Dawadi, BR, Rawat, DB, Joshi, SR, Manzoni, P. Evolutionary gaming approach for decision making of Tier-3 Internet service provider networks migration to SoDIP6 networks. Int J Commun Syst. 2020; 33:e4399, which has been published in final form at https://doi.org/10.1002/dac.4399. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving., [EN] With the increasing number of Internet of Things (IoT) devices, current networking world is suffering in terms of management and operations with lack of IPv4 addresses leading to issues like network address translation (NAT) proliferation, security and quality of services. Software-defined networking (SDN) and Internet Protocol version 6 (IPv6) are the new networking paradigms evolved to address related issues of legacy IPv4 networking. To adapt with global competitive environment and avoid all existing issues in legacy networking system, network service providers have to migrate their networks into IPv6 and SDN-enabled networks. But immediate transformations of existing network are not viable due to several factors like higher cost of migration, lack of technical human resources, lack of standards and protocols during transitions, and many more. In this paper, we present the migration analysis for proper decision making of network transition in terms of customer demand, traffic engineering, and organizational strength with operation expenditure for network migration using evolutionary gaming approach. Joint migration to SDN-enabled IPv6 network from game theoretic perspective is modeled and is validated using numerical results obtained from simulations. Our empirical analysis shows the evolutionary process of network migration while different internal and external factors in the organization affect the overall migration. Evolutionary game in migration planning is supportive in decision making for service providers to develop suitable strategy for their network migration. The proposed approach for migration decision making is mostly applicable to fairly sustained service providers who lack economics, regulation/policy, and resources strengths.

[EN] The logical separation of the data plane and the control plane of the network device conceptually defined by software-defined networking (SDN) creates many opportunities to create smart networking with better efficiency for network management and operation. SDN implementation over telecommunications (Telcos) and Internet service provider (ISP) networks is a challenging issue due to the lack of a high maturity level of SDN-based standards and several other critical factors that are considered during the real-time migration of existing legacy IPv4 networks. Different migration approaches have been studied; however, none of them seem to be close to realizing implementation. This paper implements the SDN-IP and Open Network Operating System (ONOS) SDN controller to migrate legacy IPv4 networks to multi-domain software-defined IPv6 (SoDIP6) networks and experimentally evaluate the viability of joint network migration in the ISP networks. We present results using extensive simulations for the suitable placement of the master ONOS controller during network migration by considering minimum control path latency using optimal path routing and the breadth first router replacement (BFR) technique. Our empirical analysis and evaluations show that the identification of the median router to attach the master controller and router migration planning using BFR give better results for carrier-grade legacy networks' migration to SoDIP6 networks.

We have developed new ferroelectric liquid crystalline materials with large pyroelectric coefficients (rho). Data on rho have been obtained using the Byer-Roundy technique that allows a direct determination of rho by ramping the temperature of the sample at a fixed rate. Our results show that the liquid crystalline materials developed by us exhibit rho values in the range of 30-150 nC/crm(2)K without any applied bias voltage, while rho values of 150-300 nC/cm(2)K have been observed in the presence of bias voltages. We also discuss the figure of merit of these materials for uncooled IR sensing applications., "The original document contains color images"

A new non-rubbing technique for uniform, planar alignment of liquid crystals has been developed. It involves a combination of chemisorption and UV-induced photo-dimerization. By varying chemical structure of the outermost part of the alignment layer, it has been possible to control the pretilt of the liquid crystal molecules at the surface ranging from 0 to 20 degrees. A feature of the process is that it is a room temperature process and applicable to a variety of substrates. Data on LCD cells fabricated using these alignment layers are presented.

The correlation between molecular structure and electrooptic performance is studied for novel room temperature chiral smectic A liquid crystals. It is observed that slight modifications of the hydrocarbon chain connected to the chiral center result in dramatic differences in their electrooptic performance. If the hydrocarbon chain is shortened or if a double bond is localized at the end of the hydrocarbon chain, the tilt angle, electroclinic coefficient, and switching time are significantly suppressed.

Chiral smectic A (Sm A) liquid crystals are of increasing interest because of their potential for fast analog electrooptic modulation. Chiral smectic A liquid crystals, when viewed between crossed polarizers, exhibit distinctive periodic stripe domains due to a voltage dependent deformation of the bookshelf geometry. These stripe domains reduce the contrast ratio of electrooptic devices employing these materials. This paper describes a novel optical technique to probe spatial variations in the optical properties of liquid crystals with micron resolution. The effect of the stripe formation on the electrooptic properties of a electroclinic Sm A liquid crystal, denoted as KN125, is investigated. The electric field induced stripe domains were experimentally characterized by measuring the transmission of KN125, interposed between crossed polarizers. A sharply focussed visible CW laser beam was translated across the sample with one-micron resolution. A quasi periodic modulation of the transmission due to stripe deformation of the bookshelf geometry was observed. Measurements performed within a single stripe and between adjacent stripes permitted an independent determination of the true optical tilt angle and that of the stripe deformation. The electric field dependence of the optical tilt angle for the KN125 liquid crystal is reported.

The correlation between molecular structure and electrooptic performance is studied for two series of ferroelectric liquid crystalline materials. The first series (Series 1) consist of siloxy units attached to the hydrocarbon chain at the non-chiral end of the molecule; while the second series (Series 2) contain only hydrocarbon chains at the end of the molecule. Series 1 exhibit chiral smectic A (SmA) and smectic C (SmC). It is observed that slight modifications in either the siloxy or the hydrocarbon chain length has strong effect on the electrooptic properties. Increasing the number of siloxy unit in the chain (Series 1) increases the temperature range of SmA, and reduces the SmA-SmC transition temperature. All materials have melting temperatures below room temperature, and exhibit high values of induced tilt angles. In Series 2, the materials show a broad SmA temperature range, and melting temperatures much higher than in Series 1. However, the SmA phase is found to supercool to subambient temperatures. If the hydrocarbon chain is shortened, tilt angle, electroclinic coefficient and switching time are significantly suppressed. Comparison of the electrooptic performance in SmA between the two series show that Series 1 show a much higher tilt angles than Series 2, while the later exhibit much faster response times.

Ttheory of melting

Dielectric properties of liquid crystals